Regroove brochure for Michelin truck tyres

Edition 2007
Regroove brochure
for Michelin truck tyres
Édito
Editorial
Increased mileage
increased safety
Regrooving is a key stage in optimizing the mileage of your tyres and using their full
potential.
Regrooving can in fact significantly extend a tyre's grip.
For this, when we at MICHELIN design our products we prescribe an undertread of
compound that is thick enough to allow high-quality regrooving, without affecting
the strength or toughness of the product.
This gives you increased safety, higher returns and lower fuel consumption.
Regrooving gives new sharp edges and a tread depth of about 6 to 8 mm, or about
half that of a new tyre. A regrooved tyre does not weaken the crown block. Carried out
in accordance with our recommendations, regrooving does not adversely affect
the strength of the crown block and casing.
Your Michelin advisor and your specialist dealer are the experts who can advise you.
Do not hesitate to contact them.
We would like to draw
your attention to the Michelin
group’s policy; this consists
of Michelin vigorously
defending its rights
of intellectual property
and will take legal action
against any company
or individual manufacturers
and/or marketing counterfeits
of our products.
Contents
The regrooving of truck tyres
is authorized and recommended
to improve SAFETY and ECONOMY
The principle of regrooving
Safety and regrooving
...............................................
4
................................................................
4
Retreading and regrooving
.................................................
5
Economic savings
- Mileage ...................................................................................................... 5
- Fuel consumption ...................................................................... 6
Regrooving
Tyre work
.....................................................................................................
6
..........................................................................................................
8
Legislation
...................................................................................................
Environment
............................................................................................
Recommendations
Regrooving plans
11
12
..........................................................................
12
.............................................................................
15
-3-
Regrooving
Principe
Regrooving consists of removing
some compound from the existing
undertread of compound.
For this, when a tyre is designed,
MICHELIN prescribes an undertread of
compound that is thick enough to allow
high-quality regrooving, without affecting
the strength or toughness of the product.
Tread wear indicator
Safety
Regrooving significantly extends the potential grip of a tyre.
-4-
It is carried out when there is still 2 to 4 mm
of tread depth.
Regrooving gives new sharp edges and a tread
depth of about 6 to 8 mm, or a tread depth of
about the same as that of a half-worn tyre.
Carried out in accordance with our
recommendations it has no adverse effect on
the product regarding the strength of the crown
block or casing.
Retreading
Michelin retreading =
A Michelin REMIX retread has the same advantages as a new tyre, with a constant
depth below the grooves that is adequate for high-quality regrooving.
Regrooving has no adverse effect on acceptance
for REMIX retreading.
A study shows us that out of a very large
quantity of casings presented for REMIX
retreading (1,400,000 casings), regrooved
casings have a higher rate of acceptance
(by about 3%).
This 3% increase proves that regrooving does
not adversely affect acceptance for retreading.
It is professional tyre management that is the
essential factor in acceptance for retreading.
Economy: increased mileage
Regrooving is carried out at a time in a tyre's life when it is possible to optimize
the increased mileage and the improved fuel consumption.
In fact, when a tyre is worn, the lever arm represented by each block of compound in relation
to the ground is more rigid than when the tyre is new. This minimizes the deformations of
the compound and minimizes micro-slip.
The speed of wear is slower and the rolling resistance
is lower than for a new tyre.
Regrooving makes it possible to increase the mileage
by around 20 to 25%
25
Less lever arm = less slip = less wear
Rate of wear: 1,6 mm
for 10,000 km
The deeper the tread = more slip, more deformation, more wear.
Rate of wear: 0,8 mm
for 10,000 km
-5-
Regrooving
If we look at the diagram new + regrooved + retreaded + regrooved, we can see that regrooving
gives the user a considerable saving.
By regrooving the new tyre and then the retread, the increased mileage is 50% of the mileage of
the new tyre before retreading.
1st life
2nd life
3rd life
4th life
Economy: fuel consumption
Regrooving is carried out in the phase in which the tyre has the lowest rolling resistance.
As a worn tyre has less compound deformation
in the tread pattern, it gets less hot and so
offers less rolling resistance and uses less fuel.
Regrooved tyres all positions
-6-
Improvement of 6 to 10%
in diesel fuel consumption
For given driving conditions and on a straight
road, if the rolling resistance is 100 for a new
tyre, it becomes 75 for a tyre worn to the tread
wear indicators.
Between these two extremes, the rolling
resistance is proportional to the wear.
For a tractor unit + semi-trailer vehicle
combination used for long-distance haulage,
the fuel saved by regrooving the tyres instead of
fitting new tyres can reach 2 liters per 100 kms
(according to the number of axles equipped).
New tyres all positions
If we take the example of 2 long-distance haulage users
Rolling resistance
User 1 with regrooving
Base 100
75/80
Wear
Lowest consumption
phase
Lowest consumption
phase
Regrooved
driving
Driving
Regrooved
driving
MICHELIN NEW
User 1:
Has the benefit of the phase giving lower fuel consumption.
In addition, they have the benefit of increased mileage of about 50% of the mileage of the new tyre
before regrooving.
Rolling resistance
User 2 without regrooving
Base 100
75/80
Lowest consumption phase not exploited
Wear
Driving
MICHELIN NEW
Lower performance
-7-
Regrooving
Tyre work
Work done on tyres is an important factor
in the overall performance of tyres.
Turning them round on the rim, changing their positions
and regrooving them in accordance with our recommended
rules increase tyre life.
Steering axle position tractor unit or rigid truck
For right-hand drive the left-hand front tyre wears faster
than the right-hand front tyre, and the right-hand front tyre
often has more pronounced wear on the outer shoulder
(camber of the road).
To optimize the mileage and to balance the wear between
the two tyres on the front axle, we recommend that you:
Change position
Regroove
At 50% wear
Position LH ----- RH
and Turn the right-hand
front around on the rim
Between 2 / 3 mm of
tread remaining
About 80%
rate of wear
Remove
both tyres
at the country's
legal wear limit
Regrooved fitment:
POSSIBLE
-8-
Driven axle position tractor unit
or rigid truck
As a general rule, the 2 inside twin tyres wear
more on the shoulders of the tread nearest
the inside of the chassis.
The cause:
the camber angle, the type of suspension,
the use of the retarder, the route and the load
are the main factors.
In order to even out the wear so that you can regroove
and optimize performance, we recommend that you:
Regroove/Change position
At about 80% worn.
Turn the two inside tyres round
on the rims and change position:
Interior– exterior (twin wheels)
Remove
the 4 tyres at the country's
legal wear limit
Regrooved fitment:
RECOMMANDED
-9-
Regrooving
Semi-trailer 3-axle vehicle
(TRIPLE fixed axle)
Because of the scuffing phenomenon, the tyres fitted
to the 3 axles do not wear identically.
The 3rd axle is the worst affected because of the scuffing
accentuated by the rear overhang of the vehicle.
The 1st axle, which is also affected by scuffing, wears more
quickly than the 2nd axle.
The 2nd axle, which is not affected by scuffing, has a very
low rate of wear.
If we take a base of 100 for the 3rd axle, the 1st axle is
at about 150 and the 2nd axle at about 250.
To optimize the mileage and allow regrooving:
Regroove/Change
position
At 80% wear on the 3rd axle
Regroove + Turn round on
rim and change position
3rd ---- 2nd
Regroove
At 80% wear
on the 1st axle
Regroove + Turn round
on rim
Withdraw
At the country's legal
wear limit
Regrooved fitment:
POSSIBLE
Regrooved fitment:
RECOMMENDED
Regrooved fitment:
NOT RECOMMENDED
- 10 -
Legislation
Complying with the European
legislation
Regrooving conforms to the legislation in
force in European countries.
For practically all countries, the legislation
specifies that tyres can be regrooved
on condition that the "regroovable" indicator
COUNTRY
Restrictions on
fitting regrooved tyres
GERMANY
Except front axle of cars,
speed 100 km/h*.
Except front axle of coaches,
speed 100 km/h, and transport
of dangerous materials*.
No legislation
at regrooving.
No restrictions.
AUSTRIA
BELGIUM
or the U symbol appears on the sidewalls and
that the regrooving is carried out by
professionals in accordance with good practice.
Concerning wear at removal, all countries
mention that no fabric or metal layer must be
visible on the surface and/or at the bottom of
the tread and that the tread pattern must be
visible over the whole of the tread.
Removal of tyres dues to wear
Minimum depth
Observations
1,6 mm
2 mm
1,6 mm
SPAIN
None
FRANCE
None
1 mm
ITALY
1,6 mm
1,6 mm
NETHERLANDS
None
No legislation
at regrooving.
No restrictions.
None
SWITZERLAND
None
1,6 mm
U.K.
None
1 mm
SWEDEN
None
1,6 mm
NORWAY
None
1 mm
DENMARK
FINLAND
None
None
Except single axles of coaches,
speed 100 km/h.
None
1 mm
1,6 mm
LUXEMBURG
POLAND
CZECH REP.
Nil
Tread pattern visible
over the whole tread.
Maximum permissible difference
of 5 mm on the same axle.
Nil
2 mm
For foreign vehicles
legislation of the country.
Outside twin tyres
no min depth.
3 mm for the period:
October to April.
4 mm mm for M+S radial Tyres.
1,6 mm
1,6 mm
Tyre diameter < 750 mm
3 mm
HUNGARY
Except single axles
of coaches and buses.
Tyre diameter > 750 mm
3 mm Coaches and Buses
Tyre diameter < 750 mm
5 mm Coaches and Buses
Tyre diameter > 750 mm
CROATIA
ESTONIA
REP. SLOVAKIA
SERBIA
LATVIA
LITHUANIA
SLOVENIA
BULGARIA
ROMANIA
UKRAINE
RUSSIA
None
None
None
1,6 mm
1 mm
1 mm: Tyres
2 mm: Coaches/Buses
* Prohibited on the front axles of coaches with a maximum speed of 100 km/h.
Maximum permissible difference
of 5 mm on the same axle.
Maximum permissible difference
of 5 mm on the same axle.
Maximum permissible difference
of 5 mm on the same axle.
- 11 -
Regrooving
Preservation of the environment
The regrooving of tyres extends the driving period in the lowest consumption phase.
By extending the life of the tyre, regrooving reduces the number of worn tyres
that cannot be reused.
Recommendations
Carry out the regrooving when there
is still 2 to 4 mm of tread
This precaution makes it possible to:
• Reproduce the tread pattern easily.
• Adjust the regrooving depth so as to always
keep at least 2 millimeters of compound
between the bottom of the tread pattern
and the crown layers.
Regrooving is not recommended:
If the tread shows major damage:
• Multiple holes and cuts, places where
the tread has been torn off.
• If the metal layers of the crown can be seen
through damage or cuts.
Regrooving that is too deep can:
• Result in damage that causes the premature
destruction of the casing.
• Compromise the possibility of retreading.
• Allow metal layers of the crown to appear,
which is not permitted by the legislation.
It is essential that the regrooving be carried
out by professionals in accordance with our
recommended rules.
Fitting regrooved tyres:
- 12 -
Supplier of regrooving
accessories: P.S.O.
(Pneu Service Outillage)
11, rue Gustave EIFFEL
F. 77140 NEMOURS
Tel: 33 1 64 45 00 61
Fax: 33 1 64 45 02 14
Email: infopso@pso-fr.com
It is recommended that regrooved tyres
are fitted outside snowy or icy periods.
In order avoid vehicles being immobilized
for excessively long periods during
the regrooving operation, we recommend
that you keep fitted assemblies in stock
to optimize the operation. The regrooving
operation is also a means of improving
the time management of work
in the workshop.
Equipment
Use round blades (R) only.
Comply with the part number
shown for each tread pattern.
Supplier of regrooving accessories:
P.S.O. (Pneu Service Outillage)
11, rue Gustave EIFFEL - F. 77140 NEMOURS
Tel: 33 1 64 45 00 61 - Fax: 33 1 64 45 02 14
Email: infopso@pso-fr.com
Regrooving assistance
All Michelin tyres have a regrooving well in the center of the tread wear indicators,
to allow high-quality regrooving.
The blade can also be adjusted for depth using a special jig.
- 13 -
A 2 RANGE
LONG
DISTANCE
A
MEDIUM
DISTANCE
E
Long distance. Long stages on freeways and trunk roads.
Sustained speed.
Little stress from engine or braking torques.
E 2 RANGE
For multi-purpose road use, main roads and freeways
with frequent stress from engine and braking torque.
Short distances on main roads with frequent stops.
Use on poor roads.
GRIP RANGE
GRIP
N
For road use under changeable climatic conditions,
requiring a high level of grip and winter capability
performance.
INCITY RANGE
URBAN
U
ON/OFF ROAD
Y
SITEWORK
H
For driving in urban areas with very frequent stops
(urban buses, household waste collection trucks,
highway vehicles, etc.).
Y RANGE
For general driving over short distances
and all types of road.
Access to loading and unloading points can be difficult.
H RANGE
For rough ground of site and quarry type.
Need for off-road grip.
Frequent risk of damage to tyres.
L RANGE
- 14 -
OFF-ROAD
L
For special civil or military vehicles driving
mainly on unimproved surfaces and requiring
maximum mobility.
Regrooving
plans
A 2 range
.................................................
16
E 2 range
..................................................
19
Grip range
...............................................
InCity range
............................................
23
..............................................
24
.....................................................
26
Y - H range
This diagram gives you details
of the whole of our range
according to the usage conditions.
L range
21
Regrooving
P = Depth remaining after regrooving
H = Depth of regrooving
Only regroove the areas shown in blue on the following sketch
- 15 -
Regrooving plans
A 2 range
XZA 2 ENERGY
315/60 R 22.5 XF
series 70/80 (4 grooves)
series 60 (5 grooves)
Theoretical depth
Width
of regrooving
of regrooving
series 70/80: H = 4 mm.
series 60: H = 3 mm.
Blade
8 to 10 mm.
6 to 8 mm.
R3
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
7 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
8 to 10 mm.
XZA 2
seat 17.5
XFA 1 +
385/65 R 22.5
XFA 2 ENERGY
385/55 R 22.5
- 16 -
R3
XDA 2 ENERGY
XDA 2 + ENERGY
series 80/70
series 60
Theoretical depth
Width
of regrooving
of regrooving
series 80/70: H = 4 mm.
series 60: H = 3 mm.
7 to 8 mm.
7 to 8 mm.
R3
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
7 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
6 to 8 mm.
Blade
XDA 4
X Coach
295/80 R 22.5
R3
X One XDA 2 ENERGY
495/45 R 22.5
Theoretical depth
Width
of regrooving
of regrooving
H = 3 mm.
11 to 12 mm.
XTA 2 + ENERGY
XTA 2 ENERGY
Blade
R4
series 65
series 55 and 275/70 R 22.5
Theoretical depth
Width
of regrooving
of regrooving
H = 3 mm.
8 to 10 mm.
Blade
R3
- 17 -
Regrooving plans
XTA 2 ENERGY
seat 19.5 - series 45 and 55
Theoretical depth
Width
of regrooving
of regrooving
H = 3 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
6 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
A = 7 to 9 mm.
B = 9 to 10 mm.
Blade
X One MaxiTrailer
455/45 R 22.5
XTA 2 ENERGY
seat 17.5 and 19.5 PPL
XZA
seat 20 and 22.5
- 18 The central groove must not be regrooved
- 18 -
R3 for A
R4 for B
E 2 range
XZE 2 - XZE 2 +
seat 19.5 and 22.5
Theoretical depth
Width
of regrooving
of regrooving
22.5: H = 4 mm.
19.5: H = 3 mm.
7 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
7 to 8 mm.
Blade
XZE 2
seat 17.5
R3
XZE
seat 20
Theoretical depth
Width
of regrooving
of regrooving
H = 3 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
22.5: H = 4 mm.
19.5: H = 3 mm.
7 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
7 to 8 mm.
Blade
XDE 2
XDE 2 +
seat 19.5 and 22.5
XDE 2
seat 17.5
R3
- 19 -
- 19 -
Regrooving plans
XZT
seat 17.5 and 19.5
Theoretical depth
Width
of regrooving
of regrooving
H = 3 mm.
6 to 7 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
7 to 8 mm.
Blade
XT4
R3
XTE 2
XTE 2 “R” 385/65 R 22.5
Theoretical depth
Width
of regrooving
of regrooving
series 65: H = 4 mm.
series 55: H = 3 mm.
8 to 10 mm.
8 to 10 mm.
Blade
R3
R3
XTE 2
Seat 17.5 and 19.5 - 11 R 22.5
- 20 -
Theoretical depth
Width
of regrooving
of regrooving
H = 3 mm.
6 to 8 mm.
Blade
R3
Grip range
XFN +
Theoretical depth
Width
of regrooving
of regrooving
H = 4 mm.
7 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
7 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
7 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
7 to 8 mm.
Blade
XFN 2
385/65 R 22.5
XFN 2
315/70 R 22.5
XDW Ice Grip
XDS
R3
- 21 -
Regrooving plans
XJW4+
seat 17.5/19.5
seat 22.5
Theoretical depth
Width
of regrooving
of regrooving
seat 17.5/19.5: H = 3 mm.
seat 22.5: H = 4 mm.
6 to 7 mm.
7 to 8 mm.
R3
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
6 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
6 to 8 mm.
Blade
XDN Grip
series 60
XDN 2 Grip
series 80/70
X One XDN 2 Grip
495/45 R 22.5
- 22 -
R3
InCity range
XZU - XZU +
Theoretical depth
Width
of regrooving
of regrooving
H = 4 mm.
A = 7 to 8 mm.
B = 9 to 10 mm.
R3
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
7 to 8 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
3 to 4 mm.
R3/R4
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
A = 7 to 8 mm.
B = 8 to 10 mm.
Blade
XZU 2T - XZE
335/80 R 20
X InCity
275/70 R 22.5
X One XDU
455/45 R 22.5
R4
R4
R3
R4
R3
X One XDU
495/45 R 22.5
R4
R4
R3
R4
R3
R3
R4
- 23 -
Regrooving plans
Y - H range
XZY 2
Theoretical depth
Width
of regrooving
of regrooving
H = 4 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 3 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
T* = 10 to 12 mm.
L** = 6 to 8 mm.
R4
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
T* = 10 to 12 mm.
L** = 6 to 8 mm.
Blade
295 and 315/80 R 22.5 = 4 grooves
other dimensions = 3 grooves
XZY
(17.5 - 19.5 - 6.50 to 8.25 R 20 and 9 R 22.5)
H = 4 mm.
(9.00 R 20 - 10 R 22.5 and above)
XDY 3
*transversal - **longitudinal
XDY
- 24 -
*transversal - **longitudinal
R4
R3
XZY 3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
10 to 12 mm.
R4
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
12 to 14 mm.
XTY - XTY 2
XZH 2 R
R4
- 25 -
Regrooving plans
L range
XS
Theoretical depth
Width
of regrooving
of regrooving
H = 4 mm.
8 to 10 mm.
R3
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
10 to 12 mm.
R4
Theoretical depth
Width
of regrooving
of regrooving
Blade
H = 4 mm.
A = 20 mm.
B = 10 to 12 mm.
Blade
XZL
XML
B
A
A
B
- 26 -
R4
Notes
- 27 -
Together, we'll go far
Michelin Truck Tyres
Our commitments
innovations
At MICHELIN Truck Tyres, we innovate to enable you to go further.
Innovation has been at the center of our concerns for over a century.
Each of our tyres and services are developed to provide a solution
to meet your needs. This permanent commitment is currently put into practice
by the launch of MICHELIN Durable Technologies.
mileage
MICHELIN tyres are renowned for their exceptional life-span.
Thanks to the casing endurance, our Truck tyres can be regrooved
and retreaded with MICHELIN Remix technology.
safety
MICHELIN Truck Tyres ensures that you have the most reliable tyres.
Each mile with Michelin brings you great peace of mind,
whether your tyres are new, regrooved or retreaded with MICHELIN Remix.
personalized advice
Our expertise at your service. With over 100 sales reps
and almost 250 technicians in France, we are there
to pass on our expertise and propose solutions enabling you
to reduce costs and improve competitiveness.
services
We support carriers through innovative services. Is one of your vehicles
immobilized in Europe? Thanks to the new MICHELIN Euro Assist
‘not more than 2 hours’ line of services, you will set off again
as soon as possible in cases of tyre breakdown wherever you are in Europe.
fuel savings
Because 1 full tank of fuel in 3 is due to tyre rolling resistance,
we have designed the MICHELIN A 2 ENERGY range to help carriers
cut their diesel fuel consumption. In September 2006, Michelin organized
“The CHALLENGE”, a test carried out in real conditions over 1 250 km
which confirmed that fuel savings are made using MICHELIN A 2 ENERGY
low rolling resistance tyres.
This test showed that Michelin A2 Energy low rolling resistance tyres
lead to fuel savings of up to 2.3 liters over 100 km
environmental protection
As part of its sustainable development objective, Michelin is committed
to minimizing the environmental impact of its products.
www.michelintransport.com